Hola Chia

That sentence in Spanish would be:

Lo pego en la pared. 

In this case, pared is not a direct or indirect object. It's simply a noun in a "place phrase": en la pared. In Spanish this functionality is called "complemento de lugar". 

There is no indirect object in that sentence. 

You have though a direct object pronoun which is "lo" (it)

What do I paste? "I paste it" - it (lo) is the direct object.

Saludos

Inma